I modified the below from the moderation section of Slashdot, which some indicate is one of the most effectively moderated boards on the web.

This serves as a nice guideline for all posters here:

Post intelligently: Add interesting, insightful, thought provoking comments.

Post calmly: Nobody likes a flame war. In fact, more times than not the flamer gets burned much more than their target.

Stay on topic: 'Nuff said

Be original: Avoid repeating what has already been said.

Read it before you post: Does it say what you really want it to say? Check your own spelling and grammar. This is also a good approach to checking yourself for what you're really saying.